Telemeter.



H. WILD.

' TBLEMBTER.

.APPLIGATION FILED JUNE 2,1905

Patented Nov. 9, 1909.

2 SHEETS-SHEET 1.

H. WILD.

TELEMETER.

APPLIOATION FILED JUNE 2,1908.

939,366. Patented Nov. 9, 1909.

2 SHEETS-SHEET 2.

.taining an ocular prism system an onrrnn srn rns rarnn'r canton.

HEINRICH WILD, OF JENA, GERMANY, ASSIGNOR TO THE FIRM OF CARL ZEISS, OF

' JENA, GERMANY.

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Specification of Letters Patent.

Patented Nov. 9,1909.

Application filed June 2, 1908. Serial No. 486,314.

To all whom it may concern;

Be it known thatl, HEINRICH WILD, a citizen of the German Empire, andresidin at (larl-Zeiss strasse, Jena, in the Gran Duchy ofSaxe-Weimar,Germany, have invented a new and useful Telemeter, of which thefollowing is a specification.

The invention consists in an improvement in telemeters, in which amiddle casin contwo lateral casings each containing an objective system,that is to say, an objective lens and an objective prism, are connectedtogether. The ocular prism system is situatedbefore or includes the twoimage fields and may either be arranged in front of two separateoculars, which constitute the ocular system in stereoscopic telemeters,or. in front of a common ocular, which constitutes the ocular system incoincidence telemeters. Telemeters of the kind referred to have thepeculiarity, that unfavorable differences may occur in the temperatureof the structural parts, which cause a displacement of the objectivesystems and the ocular prism sys tem relatively to each other in thedirection of sight. Hence a relative displacement results, in thedirection of the base line, of the images projected by the telescopes.This displacement of the images affords, however, derangement of theinstrument, since by means of a displacement of the same kind adjustmenthad previously been obtained. The telemeters referred to are thereforeaccording to the present invention equipped with an-appliance whichindicates any derangement due to the said displacement' This indicatingappliance does not increase the diameter of the telemeter, as it doesnot extend before the objective systems.

It comprises, as essential parts, a physical mark in each telescope, anoptical system reproducing each physical mark in an optical one,viz.,inareal image, so that a pair of control marks is formed eitherfrom one optical and one physical mark or from the two optical marks,and another optical system for magnifying the pair of control marks. Thephysical marks may serve as the measuring marks of the telemeter, partof the reproducing system may be part of the telescopes proper and themagnifying system may serve as an ocular of the telemeter. Preferablythe physical marks are arranged in the objective casings and thetelemeter according to Fig. 5.

vention. Fig. 2 is a diagrammatical plan View of the telemeter accordingto Fig. 1. Fig. 3 is a diagram of the field of view of the magnifyingsystem, appertaining to the telemeter according to Figs. 1 and 2. F 1g.4 is a diagram of the same field of view af ter displacement of the pairof control marks. Fig.' 5 is a diagrannnatical front View of a secondstereoscopic telemeter. Fig. 6 is a diagrammatical plan view of the Fig.7 is a diagram of the field of view of one of the oculars of thetelemeter according to Figs. 5 and (3, both of which oculars may act asmagnifying systems, the pair of control marks being in adjustment; Fig.8 is adiagram of the same field of view after displacement of the pairof control marks. Fig. 9 is a diagrammatical front v ew of a coincidencetelcmeter constructed according to the invention. Fig. .10 is adiagrammatical plan view of the telemeter according to Fig. 9. Fig. 11is a diagram of the field of view of the magnifying system appertainingto the telemeter according to Figs. 9 and 10, the pair of control marksbeing in adjustment. Fig. 12 is a diagram of the same field of viewafter displacement of the pair of control marks. Fig. 13 1s adiagrammatic plan view of a second coincidence telemeter. Fig. 14 is afront View partly in section of a third stereoscopic telemeter. Fig. 15is a horizontal section of the telemeter according to F ig. 14. Fig. 16IS a diagram of the field of view 'of the left ocular equipped with twooculars for stereoscopic ,measurement. The simple refiectin ob ectiveprisms a are placed in front; 0' the objective lenses 1). .The ocularprism system consists of pentagonal optical square prisms c, which areprovided with an image-erectiug ridge surface and are r'gidly connectedby a plate 0. Each ocular consists ote field lens and an eye louse,between which n rhoinboidel prisin f is or winged. By rotat the ocularsabout the ones "of the field lenses adaptation to the interpupillarydistance is obtained. The shitteble retracting prism g is the 1118l11'part of the measuring appliance. The physical marks h and. i belong tothe indicating appliance, the mark h consisting of a. long verticalstroke and the mark of two shorter, but lll'TQW-iSG vertical, strokes,the said marks being "u'ovided on the objectives. The'lens 7c being thereproducing system projects a reel. image of the mark 2 on that place ofthe left objective lens, where the mark h is situated. This image andthe mark h form the pair of control marks, the observation or which isisciliteted by the prism Z and the lenses m and it, .these three partstt'orining together the magnifying system. So long the ocular prismsystem c 0 end the objetivc systems a b, a b have undergone, no relativedisplacement in the direction oi sight, the pair of control marks isseen in the position as represented in Fig. if, llOV-YQVGI, for instance, the objective systems alone have moved toward the side oftheobserver, the pair of control marks appears in the position asrepresented in Fig. 4i, because the lens is has taken no part in themovement and the image 2? (projected by this lens) of the mark 2' (movedalong with its objective lens Z2) has therefore performed a movement inthe opposite direction to the mark It. If the telemeter be thenreadjusted, for instance, with the assistance of an object of knowndistance, it is only necessary to restore the original relative positionof the pair of control marks as shown in 3, for which purpose theshiftnble retracting prism o arranged between the mark and the lens Jr.

The objective systems of the teleineter ac cording; to 5 to 8 havepentagonal optical squire prisms a The ocular prism system consists oftwo image-erecting ridge.

prisms 0 For the indicating appliance no speciel physical marks areprovided, but the physical components 10 of the stereoscopic measuringmark, which according to Fig. '2' are arranged one in the middle of eachtelescope image field, on "the hinder surfaces of t to prisms c serve assuch marks. Each mark g) is reproduced in the plane of the other mark 1)by means of the parts c and Z) of its own telescope, the two .narrowprisms l and the parts Z) and c of the other telescope. Each mark 39 andthe image p of the other (Fig. 7) form together :1 pair of controlmarks, because, as vill be easily seen, with any relativedisplaeen'ieiu', of the coincidence telenieter be substituted for thestereoscopic ocular prism system, one of the nun-ks can be dispensedwith. The pair of control marks is in that case conmoscd from theindividual physical marl; in the one telescope held and the image ofthis mark in. the other field. in the .PTLGSEZIE case of two pairs ofcontrol marks each ocular may be used as the magnifying system of theindicating upplisnce. it is expedient to have the operture of thetelescope :ippertuiniiu; to the ocular chosen eloseo'. in observing thepair of control marks. Since the retracting prism g of the measuringappliance pairticipates in the reproduction. of both marks p, the saidobservation is only possible after having set the measuring ep tilianceupon the distance relatively to which the instrument has been adjusted,for instance, the distance infinity. it in this position of themeasuring appliance the instrument otter adjust ment shows the pair ofcontrol marks lying one above the other as in Fig. 7,. :1 relativeposition of this pair as in Fig. 8 would indicate derangement, which haserisen--if this position of the marks he observed in the rightocular--lfron1 a displacement of the objective cesings toward the sideof the observer. The prism 9 would then. have to be shifted-by settingthe nieusuriu applienceuntil the pair of control marks has taken up itsoriginal relative position. To Ire-adjust the instrun'ient deranged bythe said setting, it would be only further necesto place the index; ofthe measuring scale again. upon infinity.

in Figs. to 1.2, the objective prisms (1 Hal sqtmre prisms and each proided with. en imn. -,;eerecting Tie ocular pf system is u. separatingprism of. well known form. it is composed of it simple reflecting prismand a prism f having" three reflecting surfaces, both prisms beingcemented together. 'ihe lower half oi the cemented surface is formed asthe reflecting separating surface and is distinguished inv Fig. 9 byshading. The separating prisms two reflecting prisms Z and Z and onobjective 1* serve as the reproducing system and project real images it"and "5" (Figs. 11 and 12) of the marks it and 2'- in the iicld of viewof the ocular d c. hose two optical marks represent the pair of control.marks, and the ocular m n represents the magnifying system. ll shows thepair of control marks in actual adjustment, Fig. 12 in derangement fromthe some cause supposed to have taken place in the or examples. Theprism F can be moved, as indicated in Fig. 10, to I g'cthcr with thetelcineter ocular 5 1; toward the left, by which {he indicatingappliance is rendered inoperative and the tclemetcr available for itsproper PUIPOSC. The action and manipulation of the n'ieasuring applkarrange the marks h and 2' on these prisms.

The ridge surfaces have been transferred from the objective prisms tothe prisms and g of the separating system, but it wili be understoodthat this transfer has no infiuence upon the indicating appliance.

The stereoscopic telemeter according to Figs. 14: to 17 shows the pairof control marks h" and 71, as seen in Figs. 16 and 17, in a section ofthe image field of the left a telescope. As in the first example thispair presents a constant indication, because. its

relative position is not influenced by..the

measuring device. The real images k and 1." of the marks h andz arrangedon the ob ectives compose the pair of control marks' They are projectedby a two-part separating prism s t of the simplest form, which isarranged "on, the carrier 0" of the ocular prisms c and between theseprisms. ()n theleft ocular prism a double prism a and on the ri lit asimple prism a iscemented, both for the purpose ofiproducing theconnection between the marks h and z and the separating prism. s t, thedouble prism, however, with the further purpose of having a real imageof the pair of control marks projected into the hinder surface of theleft ocular prismc equipped with the physical component of the measuringmark, in which hinder surface the left telescope image is located. Thisreal image is produced by the objective 1' arranged with a. reflectingprism Z behind the separating prism s t. The ocular of the lefttelescope is to be considered as the magnifying system of the indicatingappliance. The pair of control marks is agaln expediently adjusted asshown in Fig. 16. A'movement of the objective casings toward the side ofthe observer must then entail an alteration of the relative position ofthe pair as shown in Fig. 17. To restore the original relative positionof the pair of control marks and at the same time to re-adjust theinstrument, the refracting prism 0 has only to be shifted, since thisprism is concerned in the production of the reflected image 0" of themark h in the same manner as in that of the left telescope image. Theright telescope is equipped with the measuring appliance, which liesbetween the objective prism of and the objective lens 6. Its main parthas the well known form of two equal refracting prisms g g rotatable inopposite di rections but through the same angle.

Regarding the mechanical arrangement according to F igs, 14 and 15, noexplanation of the construction of the main casing is required, theexternal parts a of which represent the objective casings and the middleportion of which the ocular prism casing in h meaning of thisspecification. Therhzmboidal prisms f are each combined with an eye lens6 in one casing. These ocular casings are connected with the ocularprism casing 0 so as to be each rotatablehbout the axis of the fieldlens (I. The movement of the retracting prisms g and 9 is effected bythe axle of the measuring/ drui I and the bevel wheels w, m The reracting prism 0 can by rack and pinion operated by the knob 3 Fig. let,be shifted on the slide rest 2.

I claim:

1. In a telemeter consisting of two telescopes the combination with twoobjective systems, an ocular prism system, an ocular system and ameasuring appliance, of a middle casing containing the ocular prismsystem,,two lateral casings containing the two objective systems and anappliance for indicatinga displacement of the ocular prism casing andthe objective casings relatively to each other in the direction ofsight, this appliance comprising two physical marks, located one in eachtelescope, a reproducing system for obtaining two optical marks byprojecting a real image of each physical mark, an optical mark and oneof the remaining three marks being placed together in a convenientconfiguration so as to form a pair of control marks, and a magnifyingsystem for this pair.

2. In a telemeter consisting of two telescopesthe combination with twoobjective systems, an ocular prism spstem, an ocular system and ameasuring appliance, of a middle casing containing the ocular prism system, two lateral casings containing the two objective systems, twophysical marks located one in each objective casing, a reproducingsystem located in the ocular prism casing for obtaining two opticalmarks by projecting a real image of each physical mark, an optical markand one, of the remaining three marks being placed to gether in aconvenient configuration so as to form a pair of control marks, and amagnifying system applied to this pair. I I

3. In a telemeter consisting of two telescopes the combination with twoobjective systems, an ocular prism system, an ocular system and ameasuring appliance, of a middle casing containing the ocular prismsystem, two lateral casings containing the two objectivesystems,,l.1t;wo physical marks located one in each objective casing, areproducing system, located in the ocular risni zisii r z i I inli' 2m nu 1 1 g in 1 1d i ng a. L img prism system, for obtaining two opiiicalniarkr by projecting 2i real image of each physical mark, (hose twooptical marks being placed iogeihei in a convenient configuration so asto form a pair of control marks, and a magnifying system applied to thispair. V

i. In a oeparafiing prism :elometer the combination 'Wi'ii two objectivesystems, an. ocular prism syotenn an ocular system and; :1, iueaiuringappliance, of a middle casing (:oni'uining the so Hunting prism system,two iatcmi cming's containing the two objective sys ems two physicalPlii-lks looui'od one in each obfioci'ivo cos-11mg a reproducing ssybtonlocated in the 5: viating' prism casing and including the sepzii'ziiingprism system of tho telenioteig for obfiining two optical marks byprojecting 2 iron]. image of each physical inzzrlg these two optimalnnuks being placed together in a convenient configurriiion so as to forma pair of control marks and mug nifying sysi'em zi tipiiod i0 this pair.

W itnessos PA UL Autism, FRITZ SA}; min.

